rom/graphics/xorregionregionnd.c

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Graphics function XorRegionRegion()
   6     Lang: english
   7 */
   8 #include "graphics_intern.h"
   9 #include <graphics/regions.h>
  10 #include "intregions.h"
  11
  12 /*****************************************************************************
  13
  14     NAME */
  15 #include <proto/graphics.h>
  16
  17         AROS_LH2(struct Region *, XorRegionRegionND,
  18
  19 /*  SYNOPSIS */
  20         AROS_LHA(struct Region *, R1, A0),
  21         AROS_LHA(struct Region *, R2, A1),
  22
  23 /*  LOCATION */
  24         struct GfxBase *, GfxBase, 151, Graphics)
  25
  26 /*  FUNCTION
  27         Exclusive-OR of one region with another region.
  28
  29     INPUTS
  30         region1 - pointer to a region structure
  31         region2 - pointer to a region structure
  32
  33     RESULT
  34         The resulting region or NULL in case there's no enough free memory
  35
  36     NOTES
  37         This function is not present in AmigaOS
  38
  39     EXAMPLE
  40
  41     BUGS
  42
  43     SEE ALSO
  44         AndRegionRegion(), OrRegionRegion()
  45
  46     INTERNALS
  47
  48     HISTORY
  49         27-11-96    digulla  automatically created from
  50                              graphics_lib.fd and clib/graphics_protos.h
  51         19-01-97    mreckt   intital version
  52
  53         22-09-2001  falemagn changed implementation
  54
  55 *****************************************************************************/
  56 {
  57     AROS_LIBFUNC_INIT
  58
  59     struct Region *R3;
  60
  61     if
  62     (
  63         !R1->RegionRectangle            ||
  64         !R2->RegionRectangle            ||
  65         !overlap(R1->bounds, R2->bounds)
  66     )
  67     {
  68         return OrRegionRegionND(R1, R2);
  69     }
  70
  71     R3 = NewRegion();
  72
  73     if (R3)
  74     {
  75         struct RegionRectangle *Diff1 = NULL;
  76         struct RegionRectangle *Diff2 = NULL;
  77
  78         BOOL res =
  79         _DoOperationBandBand
  80         (
  81             _ClearBandBand,
  82             MinX(R1),
  83             MinX(R2),
  84             MinY(R1),
  85             MinY(R2),
  86             R1->RegionRectangle,
  87             R2->RegionRectangle,
  88             &Diff1,
  89             &R3->bounds,
  90             GfxBase
  91         ) &&
  92         _DoOperationBandBand
  93         (
  94             _ClearBandBand,
  95             MinX(R2),
  96             MinX(R1),
  97             MinY(R2),
  98             MinY(R1),
  99             R2->RegionRectangle,
 100             R1->RegionRectangle,
 101             &Diff2,
 102             &R3->bounds,
 103             GfxBase
 104         ) &&
 105         _DoOperationBandBand
 106         (
 107             _OrBandBand,
 108             0,
 109             0,
 110             0,
 111             0,
 112             Diff1,
 113             Diff2,
 114             &R3->RegionRectangle,
 115             &R3->bounds,
 116             GfxBase
 117         );
 118
 119         _DisposeRegionRectangleList(Diff1, GfxBase);
 120         _DisposeRegionRectangleList(Diff2, GfxBase);
 121
 122         if (res)
 123         {
 124             _TranslateRegionRectangles(R3->RegionRectangle, -MinX(R3), -MinY(R3));
 125         }
 126         else
 127         {
 128             DisposeRegion(R3);
 129             R3 = NULL;
 130         }
 131     }
 132
 133     return R3;
 134
 135     AROS_LIBFUNC_EXIT
 136 }